400 amp main to feed 2- 200 amp panels

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tataco84

Member
Location
nj
This is my first post so let me give you my background real quick- about 8 years experience, mostly commercial. got my license last year and started doing my own thing. so whats new to me is doing calculations, designing installs etc.

I have a potential customer who has a farm, right now there is no electric whatsoever so the poco needs to drop poles or design something else to get elec out to the property. The closest pole is across the street and about 500 feet away from where the customer plans on putting his barn. Right now the customer just needs electric for his well pump, but in the near future he will be putting up a barn, greenhouse, as well as the lighting, receptacles and appliances that come along with that. In the distant future he may build a house on the property (lands approved for it, but its another 500-1000 feet from where the barn will be, so a total of about 1000-1500 feet from the road.

I have already contacted the poco, they need a few things from the customer, as well as load calculations from me to make sure if they run power out there they are only doing it once. Being that everything will be in the future i have no plans to go off of, so off the top of my head i was just figuring a 400 amp main, than come out of that and feed a 200 amp panel for the house (when its built), and than a 200 amp panel for the farm. I also wanted to have a disconnect for each 200 amp panel near the 400 amp main to de-energize the house, or farm if something needs to be worked on.

For my calculations i was just going to base everything off a 2500 sq ft house (customer doubts it would even be that large), all elec appliances, plus the current greenhouse, welder and farm equipment he has on his other farm. The calculations i came out with were a total load of 65,225 watts. That divided by the power coming in 240 would give me 272 amps. Which i think a 400 amp service would be fine, a little overkill but i don't know exactly the house or barn will draw.

Providing i go with 400 amp service correct me if I'm wrong, but it would be 400kcmil copper in a 3" conduit, or 600kcmil aluminum. in a 3-1/2" conduit. Would you guys typically derate the neutral for that? Also, if I'm coming into the 400 amp main in the middle of a field, the only ground required at that location would be a #4 to ground rods? Than normal grounding for a 200 amp service at the house and barn?

Another question i have is- Is there a general lighting load requirement for a barn? technically its a commercial farm, not to the public though. i don't see anything in table 220.12 for that..

Sorry for the long post but i was trying to be as detailed as possible. Is this how you guys would design this? Please give me any answers or recommendations you may have, any input is appreciated as long as its not negative.
 

John120/240

Senior Member
Location
Olathe, Kansas
Sorry for the long post but i was trying to be as detailed as possible. Is this how you guys would design this? Please give me any answers or recommendations you may have, any input is appreciated as long as its not negative.

Welcome to the Forum.

You're right the more details that you provide the more detailed response you will get. You have the general idea on your design. Have you done a load calculation per Art 220 ? Don't take negative comments the wrong way. It's constructive criticism. It is real hard to judge anybody's qualifications/work experiences thru the internet.
 

jbelectric777

Senior Member
Location
NJ/PA
Your calculations would fall under Article 547 Agricultural buildings. For the calcs it sends you to 220. Not a big article but enough to read it thoro. I did one years ago and there are rules for dust accumulation and stuff like that (moisture etc) and right off the bat underground conductors have to be insulated for live stock. 200 more than enough it sounds, Your outside of building so a 400 with double barrel lugs paralleled would work. The house you can use 4/0 SE but the farm you cant. Save some money and put the service panels at the buildings, if you want a main it doesn't have to have OCP, if it does now you have 2 feeders but its all how you wanna do it. Good luck
 

robert pitre

Member
Location
Houma,la
400 amp main to feed 2-200 amp panels

400 amp main to feed 2-200 amp panels

Welcome to the forums,this is a great place to be!
Keep in mine that disconnects must be with in site of the meter, and if meters and panels installed on one building,panels must be marked.
 

kwired

Electron manager
Location
NE Nebraska
Will POCO bring their primary voltage onto the property? If you are needing to run several hundred feet with your low voltage conductors that will mean voltage drop issues that need consideration. Around here there are lots of farm places where they will run onto property with the primary to get the source closer to the load - it is well worth it if they will do it. Then all you need to know is what size main disconnect you want, even if the load is not there now. You may put in a 400 amp main switch and equipment but POCO may still only install a 25 kVA transformer if you are not going to load it much at this time. They would rather put in the larger transformer later when it is needed.
 

robert pitre

Member
Location
Houma,la
Service equipment- Disconnecting Means

Service equipment- Disconnecting Means

Nec code 230.70 (A) 1 Readily Accessible Location, Article 230 Services.
 

jbelectric777

Senior Member
Location
NJ/PA
400

400



Why don't you just have them mount their pole and throw a temporary up so they have power, the permits good for a year but the inspector will renew it... The POCO doesn't use what we use anyway and you already told them what your load is..... When the time comes run parallel PVC service conductors down the pole, underground (follow burial rules)to each building, mount the sockets on the buildings and pop in to its load center (panel box) whats the problem? yer over thinking it trying to one up each other..... is this a modular????? because that changed years ago, an inspector can allow a service mounted on a manufactured home (and even a trailer I think but don't quote me on that, its another if the AHJ thingy) remember intersystem bonding and TWO ground rods with a #6 bare unbroken then jumper all water softners, water heaters etc etc anything that could break the continuity make sure they are jumpered or connected, for the farm read agriculture buildings, and the house gets an SEU after the lateral meter socket, im mean whats the big deal here ???????
 

tataco84

Member
Location
nj
Your calculations would fall under Article 547 Agricultural buildings. For the calcs it sends you to 220. Not a big article but enough to read it thoro. I did one years ago and there are rules for dust accumulation and stuff like that (moisture etc) and right off the bat underground conductors have to be insulated for live stock. 200 more than enough it sounds, Your outside of building so a 400 with double barrel lugs paralleled would work. The house you can use 4/0 SE but the farm you cant. Save some money and put the service panels at the buildings, if you want a main it doesn't have to have OCP, if it does now you have 2 feeders but its all how you wanna do it. Good luck


what do you mean conductors have to be insulated for live stock? technically all conductors are insulated unless they are bare.. and does it matter that there won't be livestock? its an organic farm for fruits/vegetables.. i plan on putting the panels at the buildings. could you post a link to the type of 400 main your talking about? thanks !
 

tataco84

Member
Location
nj
Why don't you just have them mount their pole and throw a temporary up so they have power, the permits good for a year but the inspector will renew it... The POCO doesn't use what we use anyway and you already told them what your load is..... When the time comes run parallel PVC service conductors down the pole, underground (follow burial rules)to each building, mount the sockets on the buildings and pop in to its load center (panel box) whats the problem? yer over thinking it trying to one up each other..... is this a modular????? because that changed years ago, an inspector can allow a service mounted on a manufactured home (and even a trailer I think but don't quote me on that, its another if the AHJ thingy) remember intersystem bonding and TWO ground rods with a #6 bare unbroken then jumper all water softners, water heaters etc etc anything that could break the continuity make sure they are jumpered or connected, for the farm read agriculture buildings, and the house gets an SEU after the lateral meter socket, im mean whats the big deal here ???????

I've thought about the temp. .honestly i probably am overthinking things, since its the first time I've ever done anything like this on my own. Can you have two services on one pole? i thought you couldn't, but maybe I'm thinking of two services to one building, which technically this isn't.. Id like one meter at the farm for commercial purposes. than one meter at the house for the residence. Its not a modular, and technically i guess i don't need to have disconnects i just thought it would be handy.
 

tataco84

Member
Location
nj
Aside from what we've been talking about do my calculations look ok? I'm going to type it out exactly how the sheet they sent me looks, which i have to return to them.. it was pretty basic, not descriptive at all...also what does the summer winter mean?

Size of main service - 400
Number of meters - 2
Neutral size - 400 kcmil cu, or 600 kcmil al
Conductor size - 400 kcmil cu, or 600 kcmil al
Conduit size - 3" for the cu, or 3-1/2" for the al
Number of sets - 1

Summer__________, Winter_________

Type of connected kw Single phase

Lighting - 15,000
Space heating - 10,000
Air conditioning
Total tons - 5,000
Water heating - 4,000
Refrigeration - 2,000
Motors
Maximum single unit hp - 1 ~5000
Cooking - 11,000
Computers - 500
Welder - 6500
Office equipment - 500
Other load - 5725
 

tataco84

Member
Location
nj
That is a lot of lighting load. Might revisit that one.

2500 sq ft house @ 3 watts per sq ft = 7500
2 small appliance branch circuits @ 1500 watts each = 3000
1 laundry circuit @ 1500 watts = 1500
2 additional small appliance branch circuits just to be safe since its for house, and farm @1500 each = 3000

7500 + 3000 + 1500 + 3000 = 15,000

1st 3000 watts @ 100% = 3000
remainder 3001-120,000... 12,000 @ 35% = 4200

3000 + 4200 = 7200

haha typed that whole thing out thinking i was going to show you i was right... than realized i used the subtotal.. everything else look ok? wire sizes? conduit sizes?
 

jbelectric777

Senior Member
Location
NJ/PA
84, I am imagining a pole that has poco leads hanging in wait for what you decide to do. My advice for now is to give them temporary power on the pole for now, it doesn't have to be large, just check that section, and when you decide to complete the work install (2) pvc conduits down the pole, underground to your home where one 200 amp meter can be and the other from the pole to the commercial barn. If there is no livestock then you don't need pvc and insulated thwn's but read that article anyway to make sure no special boxes are needed for dust or vapors, if its business I would imagine he would want his electric bill in the company name and deduct all power from his overhead and for his expenses. so basically 2 200 amp services to 2 buildings. NOW , if you want a single meter then buy a 400 amp 320 feed through and put double barrel lugs on the load side, then run your 2 service runs out of that (2-200 amps) your still outside of the building so no overcurrent protection is needed yet, however now you have to check your poco rules book as far as disconnecting means and distance and it may have to be in site and not more than 30 or 50 feet. Then just build those services. The last thought was a 400 amp rated line side and two 200 amp service entrances and build those. If you put (2) disconnects out there with fuses or breakers, now they are both feeders so there's an extra conductor for your EG in each conduit. Im just trying to save you some big bucks is all, if you do, the electrodes can be done at the pole and all your bonding can be at each main lug only panel.
 

tataco84

Member
Location
nj
84, I am imagining a pole that has poco leads hanging in wait for what you decide to do. My advice for now is to give them temporary power on the pole for now, it doesn't have to be large, just check that section, and when you decide to complete the work install (2) pvc conduits down the pole, underground to your home where one 200 amp meter can be and the other from the pole to the commercial barn. If there is no livestock then you don't need pvc and insulated thwn's but read that article anyway to make sure no special boxes are needed for dust or vapors, if its business I would imagine he would want his electric bill in the company name and deduct all power from his overhead and for his expenses. so basically 2 200 amp services to 2 buildings. NOW , if you want a single meter then buy a 400 amp 320 feed through and put double barrel lugs on the load side, then run your 2 service runs out of that (2-200 amps) your still outside of the building so no overcurrent protection is needed yet, however now you have to check your poco rules book as far as disconnecting means and distance and it may have to be in site and not more than 30 or 50 feet. Then just build those services. The last thought was a 400 amp rated line side and two 200 amp service entrances and build those. If you put (2) disconnects out there with fuses or breakers, now they are both feeders so there's an extra conductor for your EG in each conduit. Im just trying to save you some big bucks is all, if you do, the electrodes can be done at the pole and all your bonding can be at each main lug only panel.

i think your right, i probably was overthinking things.. that does seem like the best way to do it.. ill prob go with two separate 200 amps on the pole
 

growler

Senior Member
Location
Atlanta,GA
I have a potential customer who has a farm, right now there is no electric whatsoever so the poco needs to drop poles or design something else to get elec out to the property. The closest pole is across the street and about 500 feet away from where the customer plans on putting his barn. Right now the customer just needs electric for his well pump, but in the near future he will be putting up a barn, greenhouse, as well as the lighting, receptacles and appliances that come along with that. In the distant future he may build a house on the property (lands approved for it, but its another 500-1000 feet from where the barn will be, so a total of about 1000-1500 feet from the road.

I think I would try to get a power company engineer out to the site and explain what you have going on and see what they can do for you and what it's going to cost. I don't know if they will come out but around here they will.

The two service idea is the way to go but it may be better if they will use a seperate transformer if the house is 1000 ft from the barn. Now if it's only going to be 500 ft from the house to the barn then one transformer set in the middle may be just the thing (pole or pad mounted).
 

tataco84

Member
Location
nj
I think I would try to get a power company engineer out to the site and explain what you have going on and see what they can do for you and what it's going to cost. I don't know if they will come out but around here they will.

The two service idea is the way to go but it may be better if they will use a seperate transformer if the house is 1000 ft from the barn. Now if it's only going to be 500 ft from the house to the barn then one transformer set in the middle may be just the thing (pole or pad mounted).


yeah he said he will come out, once he gets the calculations from me, and the deed and site plan from the customer.
 

kwired

Electron manager
Location
NE Nebraska
I think I would try to get a power company engineer out to the site and explain what you have going on and see what they can do for you and what it's going to cost. I don't know if they will come out but around here they will.

The two service idea is the way to go but it may be better if they will use a seperate transformer if the house is 1000 ft from the barn. Now if it's only going to be 500 ft from the house to the barn then one transformer set in the middle may be just the thing (pole or pad mounted).

If the "farm" is a business, you may want a separate service that gets it's own billing anyway, the energy bill for that business is a valid business expense, so is any capital investment needed to get power to that business.
 
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